All major cholesterol-dependent cytolysins use glycans as cellular receptors

Cholesterol-dependent cytolysins (CDCs) form pores in cholesterol-rich membranes, but cholesterol alone is insufficient to explain their cell and host tropism. Here, we show that all eight major CDCs have high-affinity lectin activity that identifies glycans as candidate cellular receptors. Streptolysin O, vaginolysin, and perfringolysin O bind multiple glycans, while pneumolysin, lectinolysin, and listeriolysin O recognize a single glycan class. Addition of exogenous carbohydrate receptors for each CDC inhibits toxin activity. We present a structure for suilysin domain 4 in complex with two distinct glycan receptors, P1 antigen and αGal/Galili. We report a wide range of binding affinities for cholesterol and for the cholesterol analog pregnenolone sulfate and show that CDCs bind glycans and cholesterol independently. Intermedilysin binds to the sialyl-TF O-glycan on its erythrocyte receptor, CD59. Removing sialyl-TF from CD59 reduces intermedilysin binding. Glycan-lectin interactions underpin the cellular tropism of CDCs and provide molecular targets to block their cytotoxic activity.

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Myricetin Preferentially Binds to Interfacial Regions in Domains 1 – 3 to Inhibit Cholesterol-Dependent Cytolysins: A Molecular Docking Study

10.26434/chemrxiv.12362996 ◽

2020 ◽

Author(s):

Rafael Espiritu

Keyword(s):

Molecular Docking ◽

Structural Changes ◽

Docking Study ◽

Listeriolysin O ◽

Molecular Docking Study ◽

Docking Analysis ◽

Streptolysin O ◽

Molecule Inhibitor ◽

Human Cd59 ◽

Anthrolysin O

<p>Cholesterol-dependent cytolysins (CDCs) are proteinaceous toxins secreted as monomers by some Gram-positive and Gram-negative bacteria that contribute to their pathogenicity. These toxins bind to either cholesterol or human CD59, leading to massive structural changes, toxin oligomerization, formation of very large pores, and ultimately cell death, making these proteins promising targets for inhibition. Myricetin, and its related flavonoids, have been previously identified as a candidate small molecule inhibitor of specific CDCs such as listeriolysin O (LLO) and suilysin (SLY), interfering with their oligomerization. In this work, molecular docking was performed to assess the interaction of myricetin with other CDCs whose crystal structures are already known. Results indicated that although myricetin bound to the hitherto identified cavity in domain 4 (D4), much more efficient and stable binding was obtained in sites along the interfacial regions of domains 1 – 3 (D1 – D3). This was common among the tested CDCs, which was primarily due to much more extensive stabilizing intermolecular interactions, as indicated by post-docking analysis. Specifically, myricetin bound to (1) the interface of the three domains in anthrolysin O (ALO), perfringolysin O (PFO), pneumolysin (PLY), SLY, and vaginolysin (VLY), (2) at/near the D1/D3 interface in LLO and streptolysin O (SLO), and (3) along the D2/D3 interface in intermedilysin (ILY). These findings provide theoretical basis on the possibility of using myricetin and its related compounds as a broad-spectrum inhibitor of CDCs to potentially address the diseases associated with these pathogens.</p>

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Villin-type headpiece domains show a wide range of F-actin-binding affinities

Cell Motility and the Cytoskeleton ◽

10.1002/cm.10027 ◽

2002 ◽

Vol 52 (1) ◽

pp. 9-21 ◽

Cited By ~ 41

Author(s):

D. Vardar ◽

A. H. Chishti ◽

B. S. Frank ◽

E. J. Luna ◽

A. A. Noegel ◽

...

Keyword(s):

Actin Binding ◽

Binding Affinities ◽

Wide Range ◽

Headpiece Domains

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Class A Scavenger Receptors Are Used by Frog Virus 3 During Its Cellular Entry

Viruses ◽

10.3390/v11020093 ◽

2019 ◽

Vol 11 (2) ◽

pp. 93 ◽

Cited By ~ 3

Author(s):

Nguyen Vo ◽

Matthew Guerreiro ◽

Amulya Yaparla ◽

Leon Grayfer ◽

Stephanie DeWitte-Orr

Keyword(s):

Cellular Level ◽

Scavenger Receptors ◽

Null Cell ◽

Cellular Receptors ◽

Frog Virus 3 ◽

Frog Virus ◽

Surface Receptors ◽

Class A ◽

Wide Range ◽

Cellular Entry

Frog virus 3 (FV3) is the type species of the genus Ranavirus (family Iridoviridae). FV3 and FV3-like viruses are globally distributed infectious agents with the capacity to replicate in three vertebrate classes (teleosts, amphibians, and reptiles). At the cellular level, FV3 and FV3-like viruses can infect cells from virtually all vertebrate classes. To date, the cellular receptors that are involved in the FV3 entry process are unknown. Class A scavenger receptors (SR-As) are a family of evolutionarily conserved cell-surface receptors that bind a wide range of chemically distinct polyanionic ligands and can function as cellular receptors for other DNA viruses, including vaccinia virus and herpes simplex virus. The present study aimed to determine whether SR-As are involved in FV3 cellular entry. By using well-defined SR-A competitive and non-competitive ligand-blocking assays and absolute qPCR, we demonstrated that the SR-A competitive ligands drastically reduced the quantities of cell-associated viral loads in frog cells. Moreover, inducing the expression of a human SR-AI in an SR-A null cell line significantly increased FV3–cell association. Together, our results indicate that SR-As are utilized by FV3 during the cellular entry process.

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Molecular Targets Involved in the Neuroprotection Mediated by Terpenoids

Planta Medica ◽

10.1055/a-0953-6738 ◽

2019 ◽

Vol 85 (17) ◽

pp. 1304-1315 ◽

Cited By ~ 4

Author(s):

Laura González-Cofrade ◽

Beatriz de las Heras ◽

Luis Apaza Ticona ◽

Olga M. Palomino

Keyword(s):

Therapeutic Potential ◽

Cell Damage ◽

Biological Activities ◽

Neuronal Cell ◽

Molecular Targets ◽

Research Activity ◽

Neuroprotective Effects ◽

Therapeutic Value ◽

Wide Range ◽

Drug Leads

AbstractNatural products and their derivatives represent the most consistently successful source of drug leads. Terpenoids, a structurally diverse group, are secondary metabolites widely distributed in nature, endowed with a wide range of biological activities such as antibacterial, anti-inflammatory, antitumoral, or neuroprotective effects, which consolidate their therapeutic value. During the last decades, and taking into consideration the prevalence of aging-related diseases, research activity into the neuroprotective effects of these types of compounds has increased enormously. Several signaling pathways involved in neuroprotection are targets of their mechanism of action and mediate their pleiotropic protective activity in neuronal cell damage. In the present review, molecular basis of the neuroprotection exerted by terpenoids is presented, focusing on preclinical evidence of the therapeutic potential of diterpenoids and triterpenoids on neurodegenerative disorders. By acting on diverse mechanisms simultaneously, terpenoids have been emphasized as promising multitarget agents.

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Correlated protein conformational states and membrane dynamics during attack by pore-forming toxins

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1821897116 ◽

2019 ◽

Vol 116 (26) ◽

pp. 12839-12844 ◽

Cited By ~ 9

Author(s):

Ilanila I. Ponmalar ◽

Ramesh Cheerla ◽

K. Ganapathy Ayappa ◽

Jaydeep K. Basu

Keyword(s):

Conformational Changes ◽

Pore Formation ◽

Bacterial Infections ◽

Cell Lysis ◽

Membrane Dynamics ◽

Correlation Spectroscopy ◽

Listeriolysin O ◽

Conformational States ◽

Wide Range ◽

Membrane Bound

Pore-forming toxins (PFTs) are a class of proteins implicated in a wide range of virulent bacterial infections and diseases. These toxins bind to target membranes and subsequently oligomerize to form functional pores that eventually lead to cell lysis. While the protein undergoes large conformational changes on the bilayer, the connection between intermediate oligomeric states and lipid reorganization during pore formation is largely unexplored. Cholesterol-dependent cytolysins (CDCs) are a subclass of PFTs widely implicated in food poisoning and other related infections. Using a prototypical CDC, listeriolysin O (LLO), we provide a microscopic connection between pore formation, lipid dynamics, and leakage kinetics by using a combination of Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS) measurements on single giant unilamellar vesicles (GUVs). Upon exposure to LLO, two distinct populations of GUVs with widely different leakage kinetics emerge. We attribute these differences to the existence of oligomeric intermediates, sampling various membrane-bound conformational states of the protein, and their intimate coupling to lipid rearrangement and dynamics. Molecular dynamics simulations capture the influence of various membrane-bound conformational states on the lipid and cholesterol dynamics, providing molecular interpretations to the FRET and FCS experiments. Our study establishes a microscopic connection between membrane binding and conformational changes and their influence on lipid reorganization during PFT-mediated cell lysis. Additionally, our study provides insights into membrane-mediated protein interactions widely implicated in cell signaling, fusion, folding, and other biomolecular processes.

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Biobased Spiroimides from Itaconic Acid and Formamides: Molecular Targets for a Novel Synthetic Application of Renewable Chemicals

Synthesis ◽

10.1055/s-0040-1707318 ◽

2020 ◽

Vol 53 (02) ◽

pp. 296-308

Author(s):

Leandro Helgueira Andrade ◽

Milene Macedo Hornink ◽

Alice Uva Lopes

Keyword(s):

Itaconic Acid ◽

Biological Activities ◽

Molecular Targets ◽

Synthetic Approach ◽

Renewable Chemicals ◽

Wide Range ◽

Synthetic Application

AbstractSpiroimides exhibit a wide range of biological activities, such as anticonvulsant, antiarrhythmic, and antihyperglycemic activities. Herein, a novel synthetic application of renewable chemicals, itaconic acid and formamides, is described. Proper exploitation of the reactivity of itaconic acid and formamide allows for the development of an efficient synthetic approach for the production of several new biobased spiroimides, spiro[dihydroquinolin-2-one-succinimides] and spiro[indolin-2-one-glutarimides], in excellent overall yields (up to 98%).

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Listeriolysin O

The Journal of Cell Biology ◽

10.1083/jcb.200202121 ◽

2002 ◽

Vol 156 (6) ◽

pp. 943-946 ◽

Cited By ~ 51

Author(s):

Shaynoor Dramsi ◽

Pascale Cossart

Keyword(s):

Unique Feature ◽

Single Amino Acid ◽

Intracellular Pathogen ◽

Listeriolysin O ◽

Gram Positive Bacteria ◽

Streptolysin O ◽

Infected Cells ◽

Cell Cytosol ◽

Host Cell Cytosol ◽

Optimal Ph

Cholesterol-dependent cytolysins (CDCs)**Abbreviations used in this paper: CDC, cholesterol-dependent cytolysin; LLO, listeriolysin O; PFO, perfringolysin O; SLO, streptolysin O. are produced by a large number of pathogenic gram–positive bacteria. A member of this family, listeriolysin O (LLO), is produced by the intracellular pathogen Listeria monocytogenes. A unique feature of LLO is its low optimal pH activity (∼6) which permits escape of the bacterium from the phagosome into the host cell cytosol without damaging the plasma membrane of the infected cell. In a recent study (Glomski et al., 2002, this issue), Portnoy's group has addressed the molecular mechanism underlying the pH sensitivity of LLO. Unexpectedly, a single amino acid substitution in LLO L461T results in a molecule more active at neutral pH and promoting premature permeabilization of the infected cells, leading to attenuated virulence. This finding highlights how subtle changes in proteins can be exploited by bacterial pathogens to establish and maintain the integrity of their specific niches.

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Endocytosis of Integrin-Binding Human Picornaviruses

Advances in Virology ◽

10.1155/2012/547530 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 15

Author(s):

Pirjo Merilahti ◽

Satu Koskinen ◽

Outi Heikkilä ◽

Eveliina Karelehto ◽

Petri Susi

Keyword(s):

Economic Importance ◽

Integrin Receptors ◽

Human Parechovirus ◽

Collagen Binding ◽

Cellular Receptors ◽

Disease Symptoms ◽

Receptor Endocytosis ◽

Wide Range ◽

Coxsackievirus A9 ◽

Picornavirus Infection

Picornaviruses that infect humans form one of the largest virus groups with almost three hundred virus types. They include significant enteroviral pathogens such as rhino-, polio-, echo-, and coxsackieviruses and human parechoviruses that cause wide range of disease symptoms. Despite the economic importance of picornaviruses, there are no antivirals. More than ten cellular receptors are known to participate in picornavirus infection, but experimental evidence of their role in cellular infection has been shown for only about twenty picornavirus types. Three enterovirus types and one parechovirus have experimentally been shown to bind and use integrin receptors in cellular infection. These include coxsackievirus A9 (CV-A9), echovirus 9, and human parechovirus 1 that are among the most common and epidemic human picornaviruses and bind toαV-integrins via RGD motif that resides on virus capsid. In contrast, echovirus 1 (E-1) has no RGD and uses integrinα2β1 as cellular receptor. Endocytosis of CV-A9 has recently been shown to occur via a novel Arf6- and dynamin-dependent pathways, while, contrary to collagen binding, E-1 binds inactiveβ1 integrin and enters via macropinocytosis. In this paper, we review what is known about receptors and endocytosis of integrin-binding human picornaviruses.

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Amyotrophic Lateral Sclerosis: A Focus on Disease Progression

BioMed Research International ◽

10.1155/2014/925101 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 23

Author(s):

Ana C. Calvo ◽

Raquel Manzano ◽

Deise M. F. Mendonça ◽

María J. Muñoz ◽

Pilar Zaragoza ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Molecular Targets ◽

Therapeutic Strategies ◽

Molecular Pathways ◽

Neuron Death ◽

Parkinson’S Diseases ◽

Wide Range ◽

Motor Neuron Death ◽

Lateral Sclerosis ◽

Potential Biomarkers

Since amyotrophic lateral sclerosis (ALS) was discovered and described in 1869 as a neurodegenerative disease in which motor neuron death is induced, a wide range of biomarkers have been selected to identify therapeutic targets. ALS shares altered molecular pathways with other neurodegenerative diseases, such as Alzheimer’s, Huntington’s, and Parkinson’s diseases. However, the molecular targets that directly influence its aggressive nature remain unknown. What is the first link in the neurodegenerative chain of ALS that makes this disease so peculiar? In this review, we will discuss the progression of the disease from the viewpoint of the potential biomarkers described to date in human and animal model samples. Finally, we will consider potential therapeutic strategies for ALS treatment and future, innovative perspectives.

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